粮食中微量元素与出生缺陷的空间相关性研究

SPATIAL CORRELATION BETWEEN TRACE ELEMENTS OF GRAIN AND BIRTH DEFECTS

目的探索山东省平阴县当地粮食中As、Cd、Cr、Hg、Pb五种微量元素的含量及其地理空间分布情况,探讨微量元素与出生缺陷的关系,为筛选出生缺陷致病因子及防治措施提供依据。方法在1:1匹配病例对照研究基础上,分别采集180户缺陷儿家庭及180户正常儿家庭在孕前1年至整个孕期常食用的2种当地粮食样品,使用原子荧光光谱法和石墨炉原子吸收法进行5种元素的含量测定,使用克里金空间差值法进行空间分布预测,使用相关性分析研究空间分布上的微量元素含量与出生缺陷发生率的关系。结果(1)实际采样总计633份,样本主要为日常食用粮谷类及豆类等,其中大米/小米/小米面类的比重最高,占40.29%。(2)平阴县采集的粮食样品中As、Cd、Cr、Pb元素中位数含量均在国家安全标准范围内,而Hg元含量的中位数为0.022mg/kg,平均值为0.024mg/kg,明显高于国家规定限值,超标率达53.87%。病例组样本及对照组样本所测元素含量平均值无明显差异。(3)粮食中As、Cr、Hg、Pb元素含量在平阴县呈明显的空间分布差异;部分村镇的Hg、Pb元素含量相对较高,同时也为出生缺陷高发区。(4)粮食中Hg元素含量分布与出生缺陷发生率呈显著正相关(相关系数=0.836,P=0.010)。结论山东省平阴县当地粮食中微量元素呈现明显的空间分布差异,粮食中Hg元素浓度与出生缺陷可能具有一定相关性。

Objective To explore the contents and geographical spatial distribution of As,Cd,Cr,Hg and Pb in Pingyin county,to discuss the relationship between these five trace elements and birth defects,to provide basis for screening the pathogenic factors of birth defects and prevention measures.Methods On the basis of 1:1 case-control study,two kinds of local grain samples were collected from 180 families with defective children and 180 families with normal children respectively.The concentration of five elements were determined by atomic fluorescence spectrometry and graphite furnace atomic absorption spectrometry.The correlation analysis was used to study the relationship between the content of these trace elements and the incidence of birth defects.Results(1)A total of 633 grain samples were collected.The samples were mainly daily grains,cereals and beans,among which the group of rice/millet/millet flour had the highest proportion(40.29%).(2)The median and average contents of As,Cd,Cr and Pb in samples collected in Pingyin county were all within the scope of national security standards.While the median content of Hg element was 0.022mg/kg,and the average value was 0.024mg/kg,which was significantly higher than the national limit value,and the exceeding rate reached 53.87%.There was no significant difference in the mean value of element content between the case group and the control group.(3)The contents of Hg and Pb were relatively high in some towns,which were also with high incidence of birth defects.(4)The content of Hg in grains of Pingyin county showed a significant positive correlation with the incidence of birth defects(correlation coefficient=0.836,P=0.010).Conclusion In Pingyin county,the five trace elements in grain presented obvious spatial distribution differences.The concentration of Hg elements in grain may be correlated with birth defects.